Register Descriptions

Table 23-2describes UMR1n fields.

Table 23-2. UMR1n Field Descriptions

Bits

Name

 

 

 

 

 

 

 

 

 

 

 

Description

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

RxRTS

Receiver request-to-send. Allows the

 

 

 

output to control the

 

input of the transmitting device to prevent

RTS

CTS

 

 

receiver overrun. If both the receiver and transmitter are incorrectly programmed for

RTS

control,

RTS

control

 

 

is disabled for both. Transmitter RTS control is configured in UMR2n[TxRTS].

 

 

0 The receiver has no effect on

RTS.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 When a valid start bit is received,

RTS

is negated if the UART's FIFO is full.

RTS

is reasserted when the FIFO

 

 

 

has an empty position available.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6

RxIRQ/

Receiver interrupt select.

 

 

 

 

 

 

 

 

 

 

 

 

 

FFULL

0 RxRDY is the source that generates IRQ or DMA request.

 

 

 

 

 

 

 

 

 

 

 

1 FFULL is the source that generates IRQ or DMA request.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

ERR

Error mode. Configures the FIFO status bits, USRn[RB,FE,PE].

 

 

 

 

 

 

 

 

 

 

 

0 Character mode. The USRn values reflect the status of the character at the top of the FIFO. ERR must be 0 for

 

 

 

correct A/D flag information when in multidrop mode.

 

 

 

 

 

 

 

 

 

 

 

1 Block mode. The USRn values are the logical OR of the status for all characters reaching the top of the FIFO

 

 

 

since the last RESET ERROR STATUS command for the channel was issued. See Section 23.3.5, “UART

 

 

 

Command Registers (UCRn).”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4–3

PM

Parity mode. Selects the parity or multidrop mode for the channel. The parity bit is added to the transmitted

 

 

character, and the receiver performs a parity check on incoming data. The value of PM affects PT, as shown

 

 

below.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

PT

Parity type. PM and PT together select parity type (PM = 0x) or determine whether a data or address character is

 

 

transmitted (PM = 11).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PM

 

Parity Mode

 

Parity Type (PT= 0)

 

Parity Type (PT= 1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

00

 

With parity

 

Even parity

 

Odd parity

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

01

 

Force parity

 

Low parity

 

High parity

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

 

No parity

 

 

 

n/a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11

 

Multidrop mode

 

Data character

 

Address character

 

 

 

 

 

 

 

 

 

 

 

 

 

1–0

B/C

Bits per character. Select the number of data bits per character to be sent. The values shown do not include start,

 

 

parity, or stop bits.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

00

5 bits

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

01

6 bits

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

7 bits

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11

8 bits

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MOTOROLA

Chapter 23. UART Modules

23-5

Page 479
Image 479
Motorola MCF5281, MCF5282 2describes UMR1n fields, UMR1n Field Descriptions, Cts, Rts, Parity Mode Parity Type PT=